Purpose
Dialysis Tubing
•In this experiment we will observe passive transport of diffusion and osmosis. This experiment will show how solutions are able to move from a high concentration to a low concentration area. Also while doing this experiment, we will see how hypotonic and hypertonic solutions exist. This lab will allow us to learn how diffusion and osmosis happen in living things.
Materials
- Beakers
- Dialysis Tubing
- String
- Distilled Water
- Starch Solution
- Glucose Solution
- Iodine Solution
- Benedict's Solution
- Biuret Solution
- Test Tubes
- Hot Plates
- Electronic Balance
- Funnel
- Weigh Boat
Background
•The water is diffusing through the tubing and it can be used for diffusion with solute and osmosis,the osmosis is when water is moving through the dialysis tube so it can be equal but then the diffusion is when molecules go in and out whenever they want but it depends on the size if its small it can go through, if its big it can't.
Procedure
Hypotheses
•If the iodine solution is placed in the beaker then it will move into the dialysis tube
•If protein is placed inside the dialysis tubing then it will not move into the beaker.
•If the glucose solution is placed in the beaker then it will not move into the dialysis tube.
•If the starch solution is placed in the dialysis tube then it will move into the beaker
•It is predicted that water will move from the beaker into the dialysis tubing.
1. Obtain 1 beaker
2. Obtain 1 piece of dialysis tubing
3.. Tie a knot at one end of the dialysis tubing
4. Fill dialysis tube with Starch and Protein (with same amounts of each and record it what you put in the beaker)
5. Tie a knot on the other end of the dialysis tubing
6. Find the initial mass of dialysis tubing and record it
7. Rinse dialysis tubing under running water holding one end of the dialysis tube only
8. Place the dialysis tubing in the beaker
9. Fill the beaker with Iodine and Glucose (with same amounts of each and record it what you put in the beaker)
10. Let sit for 24 hours at room temperature
11. After 24 hours examine the beaker and do the Starch-Iodine test, observe for a change of color black/blue and decide wheather the Iodine Or Strach moved. Record It
12. Obtain a cup and take the dialysis tubing out of the beaker
13. Open the bag (inside of the cup) and empty the contain of the dialysis tubing in the cup
14. Now perform the Benedict's test to see in the Glucose diffused into the dialysis. Obtain a test tube and with a pipette add the solution that came for the dialysis tubing into the test tube. Add a pipetteful of Benedict's solution and place the test tube in boiling bath water. Observe any color change in particular a brick red color. If there is a color change than Glucose is present. Record it.
15. Now perform the Biruret test to see if Protein diffused into the beaker. Obtain a test tube and with a pipette add the solution from the beaker into the test tube. Add a pipetteful of Biruret solution. Do Not Heat! Let it sit and observe if it changes into purple if it does the Protein is present. Record it
16. After that you are done clean all used materials and dispose of contain correctly
Variables
Control Variables (What is kept the same)
-The temperature of the beaker.
-Same amount of substance inside the baggy and beaker.
Independent Variables (What was being tested)
-Protein, Starch, Iodine And Glucose.
Dependent Variables (Results)
-If Protein, Starch, Iodine and Glucose stayed or diffused.
Data Table
Possible Errors
* Not everything came out perfect nor was everything step by step perfect. We could have created errors here and there that determine our results and data. Examples not measuring the solutions exact. No heating the bath water enough. Not leaving the test tube in the boiling water enough. Not leaving the Biruet test tube sit long enough. Not have the beaker at the same temperature the 24 hours. Not letting the beaker sit 24 hours. Simple things that could have easily made our result change or could have improved the experiment if we made sure of all these things.
Discussion & Conclusion
- The Iodine diffused into the dialysis tubing. The beaker had a high concentration so it diffused into the dialysis tubing that had a low concentration to maintain equilibrium. Proving out hypothesis correct.
- Protein stayed in the dialysis tubing. The dialysis tubing had a low concentration so it stayed in the tube to maintain the equilibrium. Proving our hypothesis correct.
- Glucose moved into the dialysis tubing. The beaker had a high concentration so it diffused into the dialysis tubing that had a low concentration to maintain the equilibrium, Proving out hypothesis correct.
- And the Starch stayed into the dialysis tubing. The dialysis tubing had a low concentration so it stayed in the tube to maintain the equilibrium. Proving our hypothesis correct.
Results
* The four solutions (Starch & Iodine & Protein & Glucose) ended up all joining all together into the dialysis tubing. Showing that the beaker had hig concentration and the dialysis tube a low concentration.